Submission #1265134

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265134		vlomaczk	Olympic Bus (JOI20_ho_t4)	C++20	0 / 100	1093 ms	3260 KiB

ho_t4

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

struct Edge {
	ll a, b, c, d;
};

int M = 210;
vector<vector<pair<int, int>>> g(M);
vector<Edge> edges;

vector<ll> dijkstra(int s) {
	vector<ll> dist(M, LLONG_MAX);
	dist[s] = 0;
	priority_queue<pair<int, int>> pq;
	pq.push({0, s});
	while(pq.size()) {
		auto[dv, v] = pq.top();
		pq.pop();
		dv*=-1;
		if(dv!=dist[v]) continue;
		for(auto[u, w] : g[v]) {
			if(dv + w < dist[u]) {
				dist[u] = dv+w;
				pq.push({-dist[u], u});
			}
		}
	}
	return dist;
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	int n, m;
	cin >> n >> m;
	for(int i=0; i<m; ++i) {
		int a, b, c, d;
		cin >> a >> b >> c >> d;
		g[a].push_back({b, c});
		g[b].push_back({a, c});
		Edge e = {a, b, c, d};
		edges.emplace_back(e);
	}
	ll ans = dijkstra(1)[n] + dijkstra(n)[1];
	for(int i=0; i<m; ++i) {
		g.assign(M, vector<pair<int, int>>());
		for(int j=0; j<m; ++j) {
			auto[a,b,c,d] = edges[i];
			if(j==i) swap(a,b);
			ll sa = d + dijkstra(1)[n] + dijkstra(n)[1];
			ans = min(ans, sa);
		}
	}
	if(ans == LLONG_MAX) cout << "-1\n";
	else cout << ans << "\n";

	return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63